# HG changeset patch
# User pliden
# Date 1390901374 -3600
#      Tue Jan 28 10:29:34 2014 +0100
# Node ID a86d7639441476ad5c159f48dd671ec36b3006e5
# Parent  1e1c8d358b524b54556c9fdddcb8ad6a21ec9c81
8031703: Missing post-barrier in ReferenceProcessor

diff --git a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
@@ -5625,7 +5625,8 @@
     for (uint idx = worker_id; idx < limit; idx += stride) {
       DiscoveredList& ref_list = rp->discovered_refs()[idx];
 
-      DiscoveredListIterator iter(ref_list, &keep_alive, &always_alive);
+      DiscoveredListIterator iter(ref_list, &keep_alive, &always_alive,
+                                  false /* discovered_list_needs_barrier */);
       while (iter.has_next()) {
         // Since discovery is not atomic for the CM ref processor, we
         // can see some null referent objects.
diff --git a/src/share/vm/memory/referenceProcessor.cpp b/src/share/vm/memory/referenceProcessor.cpp
--- a/src/share/vm/memory/referenceProcessor.cpp
+++ b/src/share/vm/memory/referenceProcessor.cpp
@@ -490,13 +490,11 @@
   } else {
     new_next = _next;
   }
-
-  if (UseCompressedOops) {
-    // Remove Reference object from list.
-    oopDesc::encode_store_heap_oop((narrowOop*)_prev_next, new_next);
-  } else {
-    // Remove Reference object from list.
-    oopDesc::store_heap_oop((oop*)_prev_next, new_next);
+  // Remove Reference object from list.
+  oop_store_raw(_prev_next, new_next);
+  if (_discovered_list_needs_barrier && _prev_next != _refs_list.adr_head()) {
+    // Needs post-barrier and this is not the list head (which is not on the heap)
+    oopDesc::bs()->write_ref_field(_prev_next, new_next);
   }
   NOT_PRODUCT(_removed++);
   _refs_list.dec_length(1);
@@ -544,7 +542,7 @@
                                    OopClosure*        keep_alive,
                                    VoidClosure*       complete_gc) {
   assert(policy != NULL, "Must have a non-NULL policy");
-  DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
+  DiscoveredListIterator iter(refs_list, keep_alive, is_alive, _discovered_list_needs_barrier);
   // Decide which softly reachable refs should be kept alive.
   while (iter.has_next()) {
     iter.load_ptrs(DEBUG_ONLY(!discovery_is_atomic() /* allow_null_referent */));
@@ -584,7 +582,7 @@
                              BoolObjectClosure* is_alive,
                              OopClosure*        keep_alive) {
   assert(discovery_is_atomic(), "Error");
-  DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
+  DiscoveredListIterator iter(refs_list, keep_alive, is_alive, _discovered_list_needs_barrier);
   while (iter.has_next()) {
     iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
     DEBUG_ONLY(oop next = java_lang_ref_Reference::next(iter.obj());)
@@ -621,7 +619,7 @@
                                                   OopClosure*        keep_alive,
                                                   VoidClosure*       complete_gc) {
   assert(!discovery_is_atomic(), "Error");
-  DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
+  DiscoveredListIterator iter(refs_list, keep_alive, is_alive, _discovered_list_needs_barrier);
   while (iter.has_next()) {
     iter.load_ptrs(DEBUG_ONLY(true /* allow_null_referent */));
     HeapWord* next_addr = java_lang_ref_Reference::next_addr(iter.obj());
@@ -664,7 +662,7 @@
                                    OopClosure*        keep_alive,
                                    VoidClosure*       complete_gc) {
   ResourceMark rm;
-  DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
+  DiscoveredListIterator iter(refs_list, keep_alive, is_alive, _discovered_list_needs_barrier);
   while (iter.has_next()) {
     iter.update_discovered();
     iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
@@ -783,7 +781,7 @@
 void ReferenceProcessor::set_discovered(oop ref, oop value) {
   java_lang_ref_Reference::set_discovered_raw(ref, value);
   if (_discovered_list_needs_barrier) {
-    oopDesc::bs()->write_ref_field(ref, value);
+    oopDesc::bs()->write_ref_field(java_lang_ref_Reference::discovered_addr(ref), value);
   }
 }
 
@@ -980,7 +978,7 @@
 
 void ReferenceProcessor::clean_up_discovered_reflist(DiscoveredList& refs_list) {
   assert(!discovery_is_atomic(), "Else why call this method?");
-  DiscoveredListIterator iter(refs_list, NULL, NULL);
+  DiscoveredListIterator iter(refs_list, NULL, NULL, _discovered_list_needs_barrier);
   while (iter.has_next()) {
     iter.load_ptrs(DEBUG_ONLY(true /* allow_null_referent */));
     oop next = java_lang_ref_Reference::next(iter.obj());
@@ -1351,7 +1349,7 @@
                                                 OopClosure*        keep_alive,
                                                 VoidClosure*       complete_gc,
                                                 YieldClosure*      yield) {
-  DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
+  DiscoveredListIterator iter(refs_list, keep_alive, is_alive, _discovered_list_needs_barrier);
   while (iter.has_next()) {
     iter.load_ptrs(DEBUG_ONLY(true /* allow_null_referent */));
     oop obj = iter.obj();
diff --git a/src/share/vm/memory/referenceProcessor.hpp b/src/share/vm/memory/referenceProcessor.hpp
--- a/src/share/vm/memory/referenceProcessor.hpp
+++ b/src/share/vm/memory/referenceProcessor.hpp
@@ -99,6 +99,7 @@
   oop                _referent;
   OopClosure*        _keep_alive;
   BoolObjectClosure* _is_alive;
+  bool               _discovered_list_needs_barrier;
 
   DEBUG_ONLY(
   oop                _first_seen; // cyclic linked list check
@@ -112,7 +113,8 @@
 public:
   inline DiscoveredListIterator(DiscoveredList&    refs_list,
                                 OopClosure*        keep_alive,
-                                BoolObjectClosure* is_alive):
+                                BoolObjectClosure* is_alive,
+                                bool               discovered_list_needs_barrier):
     _refs_list(refs_list),
     _prev_next(refs_list.adr_head()),
     _prev(NULL),
@@ -126,7 +128,8 @@
 #endif
     _next(NULL),
     _keep_alive(keep_alive),
-    _is_alive(is_alive)
+    _is_alive(is_alive),
+    _discovered_list_needs_barrier(discovered_list_needs_barrier)
 { }
 
   // End Of List.